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<font color='#009900'>// Copyright (C) 2011  Davis E. King (davis@dlib.net)
</font><font color='#009900'>// License: Boost Software License   See LICENSE.txt for the full license.
</font><font color='#0000FF'>#undef</font> DLIB_AnY_FUNCTION_ABSTRACT_H_
<font color='#0000FF'>#ifdef</font> DLIB_AnY_FUNCTION_ABSTRACT_H_

<font color='#0000FF'>#include</font> "<a style='text-decoration:none' href='any_abstract.h.html'>any_abstract.h</a>"
<font color='#0000FF'>#include</font> "<a style='text-decoration:none' href='../algs.h.html'>../algs.h</a>"

<font color='#0000FF'>namespace</font> dlib
<b>{</b>

<font color='#009900'>// ----------------------------------------------------------------------------------------
</font>
    <font color='#0000FF'>template</font> <font color='#5555FF'>&lt;</font>
        <font color='#0000FF'>typename</font> function_type
        <font color='#5555FF'>&gt;</font>
    <font color='#0000FF'>class</font> <b><a name='any_function'></a>any_function</b>
    <b>{</b>
        <font color='#009900'>/*!
            REQUIREMENTS ON function_type
                This type should be a function signature.  Some examples are:
                    void (int,int)  // a function returning nothing and taking two ints
                    void ()         // a function returning nothing and taking no arguments
                    char (double&amp;)  // a function returning a char and taking a reference to a double

                The number of arguments in the function must be no greater than 10.

            INITIAL VALUE
                - is_empty() == true
                - for all T: contains&lt;T&gt;() == false

            WHAT THIS OBJECT REPRESENTS
                This object is a version of dlib::any that is restricted to containing 
                elements which are some kind of function object with an operator() which
                matches the function signature defined by function_type.


                Here is an example:
                    #include &lt;iostream&gt;
                    #include &lt;string&gt;
                    #include "dlib/any.h"
                    using namespace std;
                    void print_message(string str) { cout &lt;&lt; str &lt;&lt; endl; }

                    int main()
                    {
                        dlib::any_function&lt;void(string)&gt; f;
                        f = print_message;
                        f("hello world"); // calls print_message("hello world")
                    }

                Note that any_function objects can be used to store general function 
                objects (i.e. defined by a class with an overloaded operator()) in
                addition to regular global functions.  
        !*/</font>

    <font color='#0000FF'>public</font>:

        <font color='#009900'>// This is the type of object returned by function_type functions.
</font>        <font color='#0000FF'>typedef</font> result_type_for_function_type result_type;
        <font color='#009900'>// Typedefs defining the argument types.  If an argument does not exist
</font>        <font color='#009900'>// then it is set to void.
</font>        <font color='#0000FF'>typedef</font> type_of_first_argument_in_funct_type  arg1_type;
        <font color='#0000FF'>typedef</font> type_of_second_argument_in_funct_type arg2_type;
        ...
        <font color='#0000FF'>typedef</font> type_of_last_argument_in_funct_type   arg10_type;
        <font color='#0000FF'>const</font> <font color='#0000FF'>static</font> <font color='#0000FF'><u>unsigned</u></font> <font color='#0000FF'><u>long</u></font> num_args <font color='#5555FF'>=</font> total_number_of_non_void_arguments;

        <b><a name='any_function'></a>any_function</b><font face='Lucida Console'>(</font>
        <font face='Lucida Console'>)</font>;
        <font color='#009900'>/*!
            ensures
                - this object is properly initialized
        !*/</font>

        <b><a name='any_function'></a>any_function</b> <font face='Lucida Console'>(</font>
            <font color='#0000FF'>const</font> any_function<font color='#5555FF'>&amp;</font> item
        <font face='Lucida Console'>)</font>;
        <font color='#009900'>/*!
            ensures
                - copies the state of item into *this.  
                - Note that *this and item will contain independent copies of the
                  contents of item.  That is, this function performs a deep
                  copy and therefore does not result in *this containing
                  any kind of reference to item.
        !*/</font>

        <font color='#0000FF'>template</font> <font color='#5555FF'>&lt;</font> <font color='#0000FF'>typename</font> T <font color='#5555FF'>&gt;</font>
        <b><a name='any_function'></a>any_function</b> <font face='Lucida Console'>(</font>
            <font color='#0000FF'>const</font> T<font color='#5555FF'>&amp;</font> item
        <font face='Lucida Console'>)</font>;
        <font color='#009900'>/*!
            ensures
                - #contains&lt;T&gt;() == true
                - #cast_to&lt;T&gt;() == item
                  (i.e. a copy of item will be stored in *this)
        !*/</font>

        <font color='#0000FF'><u>void</u></font> <b><a name='clear'></a>clear</b> <font face='Lucida Console'>(</font>
        <font face='Lucida Console'>)</font>;
        <font color='#009900'>/*!
            ensures
                - #*this will have its default value.  I.e. #is_empty() == true
        !*/</font>

        <font color='#0000FF'>template</font> <font color='#5555FF'>&lt;</font><font color='#0000FF'>typename</font> T<font color='#5555FF'>&gt;</font>
        <font color='#0000FF'><u>bool</u></font> <b><a name='contains'></a>contains</b> <font face='Lucida Console'>(</font>
        <font face='Lucida Console'>)</font> <font color='#0000FF'>const</font>;
        <font color='#009900'>/*!
            ensures
                - if (this object currently contains an object of type T) then
                    - returns true
                - else
                    - returns false
        !*/</font>

        <font color='#0000FF'><u>bool</u></font> <b><a name='is_empty'></a>is_empty</b><font face='Lucida Console'>(</font>
        <font face='Lucida Console'>)</font> <font color='#0000FF'>const</font>;
        <font color='#009900'>/*!
            ensures
                - if (this object contains any kind of object) then
                    - returns false 
                - else
                    - returns true 
        !*/</font>

        <font color='#0000FF'><u>bool</u></font> <b><a name='is_set'></a>is_set</b> <font face='Lucida Console'>(</font>
        <font face='Lucida Console'>)</font> <font color='#0000FF'>const</font>;
        <font color='#009900'>/*!
            ensures
                - returns !is_empty()
        !*/</font>

        result_type <b><a name='operator'></a>operator</b><font face='Lucida Console'>(</font><font face='Lucida Console'>)</font> <font face='Lucida Console'>(</font>
        <font face='Lucida Console'>)</font> <font color='#0000FF'>const</font>;
        <font color='#009900'>/*!
            requires
                - is_empty() == false
                - the signature defined by function_type takes no arguments
            ensures
                - Let F denote the function object contained within *this.  Then
                  this function performs:
                    return F()
                  or if result_type is void then this function performs:
                    F()
        !*/</font>

        result_type <b><a name='operator'></a>operator</b><font face='Lucida Console'>(</font><font face='Lucida Console'>)</font> <font face='Lucida Console'>(</font>
            <font color='#0000FF'>const</font> arg1_type<font color='#5555FF'>&amp;</font> a1
        <font face='Lucida Console'>)</font> <font color='#0000FF'>const</font>;
        <font color='#009900'>/*!
            requires
                - is_empty() == false
                - the signature defined by function_type takes one argument
            ensures
                - Let F denote the function object contained within *this.  Then
                  this function performs:
                    return F(a1)
                  or if result_type is void then this function performs:
                    F(a1)
        !*/</font>

        result_type <b><a name='operator'></a>operator</b><font face='Lucida Console'>(</font><font face='Lucida Console'>)</font> <font face='Lucida Console'>(</font>
            <font color='#0000FF'>const</font> arg1_type<font color='#5555FF'>&amp;</font> a1,
            <font color='#0000FF'>const</font> arg2_type<font color='#5555FF'>&amp;</font> a2
        <font face='Lucida Console'>)</font> <font color='#0000FF'>const</font>;
        <font color='#009900'>/*!
            requires
                - is_empty() == false
                - the signature defined by function_type takes two arguments
            ensures
                - Let F denote the function object contained within *this.  Then
                  this function performs:
                    return F(a1,a2)
                  or if result_type is void then this function performs:
                    F(a1,a2)
        !*/</font>

        <font color='#009900'>/* !!!!!!!!!  NOTE  !!!!!!!!!

           In addition to the above, operator() is defined for up to 10 arguments.
           They are not listed here because it would clutter the documentation. 

           !!!!!!!!!  NOTE  !!!!!!!!!  */</font>

        <font color='#0000FF'>template</font> <font color='#5555FF'>&lt;</font><font color='#0000FF'>typename</font> T<font color='#5555FF'>&gt;</font>
        T<font color='#5555FF'>&amp;</font> <b><a name='cast_to'></a>cast_to</b><font face='Lucida Console'>(</font>
        <font face='Lucida Console'>)</font>;
        <font color='#009900'>/*!
            ensures
                - if (contains&lt;T&gt;() == true) then
                    - returns a non-const reference to the object contained within *this
                - else
                    - throws bad_any_cast
        !*/</font>

        <font color='#0000FF'>template</font> <font color='#5555FF'>&lt;</font><font color='#0000FF'>typename</font> T<font color='#5555FF'>&gt;</font>
        <font color='#0000FF'>const</font> T<font color='#5555FF'>&amp;</font> <b><a name='cast_to'></a>cast_to</b><font face='Lucida Console'>(</font>
        <font face='Lucida Console'>)</font> <font color='#0000FF'>const</font>;
        <font color='#009900'>/*!
            ensures
                - if (contains&lt;T&gt;() == true) then
                    - returns a const reference to the object contained within *this
                - else
                    - throws bad_any_cast
        !*/</font>

        <font color='#0000FF'>template</font> <font color='#5555FF'>&lt;</font><font color='#0000FF'>typename</font> T<font color='#5555FF'>&gt;</font>
        T<font color='#5555FF'>&amp;</font> <b><a name='get'></a>get</b><font face='Lucida Console'>(</font>
        <font face='Lucida Console'>)</font>;
        <font color='#009900'>/*!
            ensures
                - #is_empty() == false
                - #contains&lt;T&gt;() == true
                - if (contains&lt;T&gt;() == true)
                    - returns a non-const reference to the object contained in *this.
                - else
                    - Constructs an object of type T inside *this
                    - Any previous object stored in this any_function object is destructed and its
                      state is lost.
                    - returns a non-const reference to the newly created T object.
        !*/</font>

        any_function<font color='#5555FF'>&amp;</font> <b><a name='operator'></a>operator</b><font color='#5555FF'>=</font> <font face='Lucida Console'>(</font>
            <font color='#0000FF'>const</font> any_function<font color='#5555FF'>&amp;</font> item
        <font face='Lucida Console'>)</font>;
        <font color='#009900'>/*!
            ensures
                - copies the state of item into *this.  
                - Note that *this and item will contain independent copies of the
                  contents of item.  That is, this function performs a deep
                  copy and therefore does not result in *this containing
                  any kind of reference to item.
        !*/</font>

        <font color='#0000FF'><u>void</u></font> <b><a name='swap'></a>swap</b> <font face='Lucida Console'>(</font>
            any_function<font color='#5555FF'>&amp;</font> item
        <font face='Lucida Console'>)</font>;
        <font color='#009900'>/*!
            ensures
                - swaps *this and item
        !*/</font>

    <b>}</b>;

<font color='#009900'>// ----------------------------------------------------------------------------------------
</font>
    <font color='#0000FF'>template</font> <font color='#5555FF'>&lt;</font>
        <font color='#0000FF'>typename</font> function_type
        <font color='#5555FF'>&gt;</font>
    <font color='#0000FF'>inline</font> <font color='#0000FF'><u>void</u></font> <b><a name='swap'></a>swap</b> <font face='Lucida Console'>(</font>
        any_function<font color='#5555FF'>&lt;</font>function_type<font color='#5555FF'>&gt;</font><font color='#5555FF'>&amp;</font> a,
        any_function<font color='#5555FF'>&lt;</font>function_type<font color='#5555FF'>&gt;</font><font color='#5555FF'>&amp;</font> b
    <font face='Lucida Console'>)</font> <b>{</b> a.<font color='#BB00BB'>swap</font><font face='Lucida Console'>(</font>b<font face='Lucida Console'>)</font>; <b>}</b>
    <font color='#009900'>/*!
        provides a global swap function
    !*/</font>

<font color='#009900'>// ----------------------------------------------------------------------------------------
</font>
    <font color='#0000FF'>template</font> <font color='#5555FF'>&lt;</font>
        <font color='#0000FF'>typename</font> T,
        <font color='#0000FF'>typename</font> function_type
        <font color='#5555FF'>&gt;</font> 
    T<font color='#5555FF'>&amp;</font> <b><a name='any_cast'></a>any_cast</b><font face='Lucida Console'>(</font>
        any_function<font color='#5555FF'>&lt;</font>function_type<font color='#5555FF'>&gt;</font><font color='#5555FF'>&amp;</font> a
    <font face='Lucida Console'>)</font> <b>{</b> <font color='#0000FF'>return</font> a.cast_to<font color='#5555FF'>&lt;</font>T<font color='#5555FF'>&gt;</font><font face='Lucida Console'>(</font><font face='Lucida Console'>)</font>; <b>}</b>
    <font color='#009900'>/*!
        ensures
            - returns a.cast_to&lt;T&gt;()
    !*/</font>

<font color='#009900'>// ----------------------------------------------------------------------------------------
</font>
    <font color='#0000FF'>template</font> <font color='#5555FF'>&lt;</font>
        <font color='#0000FF'>typename</font> T,
        <font color='#0000FF'>typename</font> function_type
        <font color='#5555FF'>&gt;</font> 
    <font color='#0000FF'>const</font> T<font color='#5555FF'>&amp;</font> <b><a name='any_cast'></a>any_cast</b><font face='Lucida Console'>(</font>
        <font color='#0000FF'>const</font> any_function<font color='#5555FF'>&lt;</font>function_type<font color='#5555FF'>&gt;</font><font color='#5555FF'>&amp;</font> a
    <font face='Lucida Console'>)</font> <b>{</b> <font color='#0000FF'>return</font> a.cast_to<font color='#5555FF'>&lt;</font>T<font color='#5555FF'>&gt;</font><font face='Lucida Console'>(</font><font face='Lucida Console'>)</font>; <b>}</b>
    <font color='#009900'>/*!
        ensures
            - returns a.cast_to&lt;T&gt;()
    !*/</font>

<font color='#009900'>// ----------------------------------------------------------------------------------------
</font>
<b>}</b>

<font color='#0000FF'>#endif</font> <font color='#009900'>// DLIB_AnY_FUNCTION_ABSTRACT_H_
</font>

</pre></body></html>